Lock读写锁机制可以实现！
在Java中Lock接口比synchronized块的优势是什么？
Lock接口最大的优势是为读和写分别提供了锁。
代码语言：javascript复制 1 import java.text.SimpleDateFormat;
2 import java.util.Date;
3 import java.util.Random;
4 import java.util.concurrent.locks.ReadWriteLock;
5 import java.util.concurrent.locks.ReentrantReadWriteLock;
6
7
8
9
10 public class JoinTest2 {
11
12 public static void main(String[] args) {
13 final TheData theData = new TheData();
14 for(int i=0;i<4;i ){
15 new Thread(new Runnable() {
16 @Override
17 public void run() {
18 theData.get();
19 }
20 }).start();
21 }
22 for(int i=0;i<4;i ){
23 new Thread(new Runnable() {
24 @Override
25 public void run() {
26 theData.put(new Random().nextInt(1000));
27 }
28 }).start();
29 }
30 }
31
32
33 }
34
35 class TheData{
36 private Integer data = 0;
37 private ReadWriteLock rwLock = new ReentrantReadWriteLock();
38 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
39 public void get(){
40 rwLock.readLock().lock();//读锁开启，读进程均可进入
41 try{//用try finally来防止因异常而造成的死锁
42 System.out.println(Thread.currentThread().getName() "read lock is ready.." sdf.format(new Date()));
43 Thread.sleep(1000);
44 System.out.println(Thread.currentThread().getName() "read data is" data);
45 }catch (InterruptedException e) {
46 e.printStackTrace();
47 }finally{
48 rwLock.readLock().unlock();//读锁解锁
49 }
50 }
51
52 public void put(Integer data){
53 rwLock.writeLock().lock();//写锁开启，这时只有一个写线程进入
54 try{//用try finally来防止因异常而造成的死锁
55 System.out.println(Thread.currentThread().getName() "write lock is ready.." sdf.format(new Date()));
56 Thread.sleep(1000);
57 this.data = data;
58 System.out.println(Thread.currentThread().getName() "write data is" data);
59
60 }catch (InterruptedException e) {
61 e.printStackTrace();
62 }finally{
63 rwLock.writeLock().unlock();//写锁解锁
64 }
65 }
66 }运行结果如下：
